Energy generating roof system

ABSTRACT

An energy generating system comprising a conduit comprising an energy collection portion and a heat exchange portion, wherein the energy collection portion of the conduit is located within an air filled space or a sewer gas exhaust pipe or a ventilation duct, wherein the conduit is adapted to transport a first fluid, wherein the first fluid is adapted to absorb thermal energy when passing through the energy collection portion of the conduit and a first heat exchanger adapted to exchange heat with the first fluid passing through the heat exchange portion of the conduit.

FIELD

The invention relates generally to a system for collecting thermalenergy, and more particularly to a system for collecting thermal energyfrom a building roof and/or from sewer gas.

INTRODUCTION

Energy use, such as electricity or energy from burning fossil fuels, isone of the main expenditures associated with maintaining a building.Reducing the energy required to maintain the building would greatlyreduce the cost of maintaining the building and the environmentalfootprint of a building. Accordingly, it would be desirable to collectenergy from other sources which are available without cost.

SUMMARY

The invention provides in one aspect an energy generating roof systemfor a building roof comprising:

a plurality of roof support members;

a substantially planar vapor barrier located above the roof supportmembers and operatively connected thereto;

a plurality of spacing members located above the vapor barrier andsecured to the roof support members;

a roof covering operatively connected to the spacing members, whereinthe roof covering and the vapor barrier define an air filled spacetherebetween;

a conduit comprising an energy collection portion and a heat exchangeportion, wherein the energy collection portion of the conduit is locatedwithin the air filled space, wherein the conduit is adapted to transporta first fluid, wherein the first fluid is adapted to absorb thermalenergy when passing through the energy collection portion of theconduit; and

a first heat exchanger adapted to exchange heat with the first fluidpassing through the heat exchange portion of the conduit.

The invention provides in another aspect a sewer gas heat recoverysystem comprising;

a sewer gas exhaust pipe;

a heat recovery conduit comprising an energy collection portion and aheat exchange portion, wherein the energy collection portion of the heatrecovery conduit is located within the sewer gas exhaust pipe, whereinthe heat recovery conduit is adapted to transport a first heat recoveryfluid wherein the first heat recovery fluid is adapted to absorb thermalenergy when passing through the energy collection portion of the heatrecovery conduit; and

a first heat exchanger adapted to exchange heat with the first heatrecovery fluid passing through the heat exchange portion of the heatrecovery conduit.

The invention provides in still another aspect a combined sewer gas heatrecovery and energy generating roof system comprising:

an energy generating roof system (EGRS) comprising:

-   -   a plurality of roof support members,    -   a substantially planar vapor barrier located above the roof        support members and operatively connected thereto,    -   a plurality of spacing members located above the vapor barrier        and secured to the roof support members,    -   a roof covering operatively connected to the spacing members,        wherein the roof covering and the vapor barrier define an air        filled space therebetween, and    -   a EGRS conduit comprising an energy collection portion, wherein        the energy collection portion of the conduit is located within        the air filled space, wherein the conduit is adapted to        transport a first fluid, wherein the first fluid is adapted to        absorb thermal energy when passing through the energy collection        portion of the conduit;

a sewer gas heat recovery system (SGHRS) comprising:

-   -   a sewer gas exhaust pipe, and    -   a SGHRS conduit comprising an energy collection portion, wherein        the energy collection portion of the SGHRS conduit is located        within the sewer gas exhaust pipe, wherein the SGHRS conduit is        adapted to transport the first fluid wherein the first fluid is        adapted to absorb thermal energy when passing through the energy        collection portion of the SGHRS conduit;

a first heat exchanger adapted to exchange heat with the first fluid;and

a switching valve in fluid communication with the EGRS conduit and theSGHRS conduit, wherein the switching valve is operable between:

-   -   a first position wherein the first fluid is directed through the        energy collection portion of the SGHRS conduit but is prevented        from passing through the energy collection portion of the EGRS        conduit;    -   a second position wherein the first fluid is directed through        the energy collection portion of the SGHRS conduit and through        the energy collection portion of the EGRS conduit; and    -   a third position wherein the first fluid is directed through the        energy collection portion of the EGRS conduit but is prevented        from passing through the energy collection portion of the SGHRS        conduit.

DRAWINGS

For a better understanding of the embodiments described herein and toshow more clearly how they may be carried into effect, reference willnow be made, by way of example only, to the accompanying drawings whichshow at least one exemplary embodiment, and in which:

FIG. 1 is a cross-sectional front view of a roof structure according toan embodiment of an energy generating roof system;

FIG. 2 is a cross-sectional side view of a roof structure according toan embodiment of the energy generating roof system for collectingthermal energy from a roof;

FIG. 3 is a partial schematic view of an embodiment of an energygenerating roof system for collecting thermal energy from a roof;

FIG. 4. is a partial schematic view of an energy collection portion of aconduit within two exemplary roofs;

FIG. 5. is a schematic view of area A of FIG. 4;

FIG. 6. is a partial schematic view of another embodiment of the energygenerating roof system for collecting thermal energy from a roof;

FIG. 7. is a partial schematic view of an embodiment of an energycollection system for collecting energy from sewer gas;

FIG. 8. is a partial schematic view of yet another embodiment of theenergy generating roof system; and

FIG. 9 is a schematic view of a building illustrating the location ofthe heat recovery conduit of the embodiment of FIG. 7.

DESCRIPTION OF VARIOUS EMBODIMENTS

Referring to FIGS. 1 and 2, an exemplary roof 9 of energy generatingroof system (EGRS) 10 is shown. Roof 9 may be of any type including,without limitation, a flat roof, a gable roof, a cross gable roof, amansard roof, a hipped roof, a cross-hipped roof, a pyramidal roof, ashed roof, a saltbox roof and a gambrel roof. Roof 9 includes one ormore roof support members 1, vapor barrier 2, spacing members 6 and aroof covering 5.

Vapor barrier 2 is located above and operatively connected to the one ormore roof support members 1. The vapor barrier may be a plastic film orany other suitable material. In some embodiments, a roof support member1 may be a joist, beam or rafter. An intermediate layer 3, such asplywood sheets, metal sheets, or lumber, may be located above andsecured to roof support members 1 in any suitable manner, such as byfasteners. The vapor barrier 2 may cover the intermediate layer 3.

Spacing members 6 are located above the vapor barrier 2 and arepreferably secured to the roof support members 1 in any suitablefashion, such as by fasteners. Preferably, spacing members 6 are spacedapart and are parallel to each other. In some embodiments, cross members4 are located above spacing members 6 and secured to the spacing members6 via fasteners. Cross members 4 may be parallel to each other andoriented at an angle (such as a 90 degree angle) to the spacing members6. In some embodiments, spacing members 6 may be strapping. In yet otherembodiments the, cross members 4 may be part of the spacing memberstructure.

The roof covering 5 is located above and is secured to preferablyspacing members 6. Roof covering 5 may be of any type including, withoutlimitation, steel, shingle, clay, cedar, and concrete. The roof covering5 and the vapor barrier 2 define an air filled space 8 therebetween.Located within the air filled space 8 may be spacing members 6 and otherroof elements.

Referring now to FIG. 3, a schematic of the first embodiment of EGRS 10is shown. EGRS 10 includes a conduit 11 which transports a first fluid17. Conduit 11 may be of any suitable type and cross-section. In someembodiments, conduit 11 may be a pipe or a hose. Conduit 11 includes anenergy collection portion 12 and a heat exchange portion 13. Preferably,the energy collection portion 12 of conduit 11 is arranged in a tortuousor undulating path within the air filled space 8. In some embodiments,energy collection portion 12 includes a plurality of straight segmentsand 180 degree elbows (shown in FIGS. 4 and 5). Further, the straightsegments may substantially align with the spaces in between the spacingmembers 6 (shown in FIGS. 4 and 5). A pump 14 circulates the first fluid17 within the conduit 11. It will be appreciated that factors, such assolar radiation and heat rising from the interior of the building maycause the air temperature within the air filled space 8 to rise relativeto the ambient temperature. The thermal energy in the air filled space 8heats the first fluid 17 as it passes through the energy collectionportion 12 of conduit 11.

The pump 14 circulates the heated first fluid through the heat exchangeportion 13 of conduit 11 which is located in a first heat exchanger 16of a first thermocompressor 15. The first heat exchanger 16 may be avessel in which the heat exchange portion 13 of conduit 11 is located.Preferably, the heat exchange portion 13 is a coil (not shown) withinthe vessel. A second fluid 18 passes through the vessel outside thecoil. First heat exchanger 16 exchanges heat between the first fluid 17and the second fluid 18 which circulates through first thermocompressor15. First thermocompressor 15 comprises first heat exchanger 16, firstcompressor 19, second heat exchanger 20, first throttle valve 21, thesecond fluid 18, and a line 50 through which the second fluid 18 flowsbetween the above components. First and second fluids 17, 18 may be anyfluids suitable for retaining and transmitting heat. In someembodiments, the first fluid 17 may be water or a water antifreezemixture, and the second fluid 18 is preferably a refrigerant. Inexemplary embodiments, as shall be described below, second fluid 18 maybe present in one or both of gaseous and liquid states at various pointsas it circulates within thermocompressor 15. Specifically, the exchangeof heat from first fluid 17 to second fluid 18 at first heat exchanger16 may cause second fluid 18 to evaporate. Evaporated second fluid 18 iscompressed by first compressor 19 to raise the pressure of the secondfluid 18 as it passes through the first compressor 19. This also has theeffect of heating second fluid 18 to an elevated temperature. Thegaseous second fluid 18 then flows through second heat exchanger 20which facilitates the exchange of heat between the gaseous second fluid18 and a third fluid 22 circulating through second conduit 24.Preferably, the second heat exchanger is identical to the first heatexchanger 16. The loss of heat from second fluid 18 to third fluid 22causes gaseous second fluid 18 to cool and condense into a liquid. Thethrottle valve 21 permits the second fluid to expand, reducing thepressure of the second fluid 18. The reduction in pressure permitssecond fluid 18 to evaporate at lower temperatures within first heatexchanger 16.

In some embodiments, third fluid 22 circulating in second conduit 24,heated from circulating through second heat exchanger 20 is adapted topass through at least one radiator 23 connected to second conduit 24.The radiator 23 heats a building or room where it is located. In otherembodiments, third fluid 22 may pass into the hot water pipe system of abuilding. Any embodiments described herein where fluid is said to passthrough at least one radiator 23, will be understood to includealternative embodiments where that fluid is instead the hot water sourcefor a building.

First and second heat exchangers 16, 20 may be any heat exchangersuitable for transferring heat between fluids. These may include,without limitation, shell and tube heat exchangers, plate heatexchangers, regenerative heat exchangers, spiral heat exchangers,cross-flow heat exchangers, parallel flow heat exchangers andphase-change heat exchangers. The selection of heat exchangers 16, 20may be based at least in part on the selected elemental states (e.g.gaseous or liquid) of the fluids passing through each respective heatexchanger. As explained above, while the particular implementationdescribed herein includes a second fluid 18 which passes between liquidand gaseous states, other embodiments may utilize a second fluid whichremains in a single state (e.g. either gaseous or liquid).

In operation, a first fluid 17 is circulated by pump 14 from the outletof first heat exchanger 16 to the energy collection portion 12 ofconduit 11 inside the air filled space 8 of the roof 9. The relativelyhotter air in the air filled space 8 heats the first fluid 17 in theenergy collection portion 12 of conduit 11. The temperature of the airfilled space 8 and the amount of warming the first fluid 17 undergoesdepends on the season and the climate in which the building is located.First fluid 17 then passes through heat exchange portion 13 of conduit11 located in the first heat exchanger 16. First fluid 17, entering thefirst heat exchanger 16 at an elevated temperature, exchanges heat withsecond fluid 18 which enters the first heat exchanger 16 at a lowertemperature. The transfer of heat energy into second fluid 18 causessecond fluid 18 to evaporate. Gaseous second fluid 18 has a temperatureon the order of +6° C. when it enters first compressor 19 which raisesthe pressure and temperature of second fluid 18 to a temperature in therange of about +35° C. to +65° C. The gaseous second fluid 18 is thencondensed into a liquid as it passes through second heat exchanger 20and transfers heat to third fluid 22. Before re-entering first heatexchanger 16, the pressure of liquid second fluid 18 is reduced at afirst throttle valve 21. Third fluid 22, circulating through secondconduit 24, exits second heat exchanger 20 after receiving heat fromsecond fluid 18 at a temperature of about 65° C. before passing throughone or more radiators 23 which are adapted to heat a building.

Further reference is now made to FIG. 6 in which a second exemplaryembodiment is shown that may be particularly suitable when the outsidetemperature is especially low. In this embodiment, a secondthermocompressor 32 is situated intermediate the first thermocompressor15 and the one or more radiators 23. The components of the firstthermocompressor 15 are identical to those described in the firstembodiment, and will not be further described. Second thermocompressor32 includes a third heat exchanger 25, second compressor 27, fourth heatexchanger 28, second throttle valve 29 and fourth fluid 26, all of whichare connected by second line 60. Instead of the third fluid 22 flowingthrough one or more radiators 23, it flows through the third heatexchanger 25 of second thermocompressor 32.

Third heat exchanger 25 exchanges heat between third fluid 22 and fourthfluid 26 which circulates through second thermocompressor 32. Third andfourth fluids 22, 26 may be any fluids known in the art suitable forretaining and transmitting heat. In some embodiments, third and fourthfluids 22, 26 may be a refrigerant. In exemplary embodiments, as shallbe described below, fourth fluid 26 may be present in one or both ofgaseous and liquid forms at various points within secondthermocompressor 32 as it circulates therethrough. Specifically, theexchange of heat from third fluid 22 to fourth fluid 26 at third heatexchanger 25 may cause fourth fluid 26 to evaporate. Evaporated fourthfluid 26 is compressed by second compressor 27, heating fourth fluid 26to an elevated temperature and pressure. The gaseous fourth fluid 26flows through fourth heat exchanger 28 which exchanges heat betweengaseous fourth fluid 26 and fifth fluid 31 circulating through thirdconduit 30. The loss of heat from fourth fluid 26 to fifth fluid 31causes gaseous fourth fluid 26 to cool and condense into a liquid. As itpasses through second throttle valve 29, the fourth fluid 26 expands(i.e. has its pressure reduced).

In operation, ambient outside air temperature may be as low as −30° C.or lower. In a manner similar to as described with respect to the firstembodiment, very cold first fluid 17 circulates into the energycollection portion 12 of conduit 11 and is heated therein. The firstfluid 17, now with an elevated temperature, passes through the firstheat exchanger 16, exchanging heat with second fluid 18. Second fluid 18evaporates from the receipt of heat from first fluid 17 and enters firstcompressor 19 with a temperature on the order of −26° C. The firstcompressor 19 compresses the second fluid 18 to an elevated temperatureand pressure. Second fluid 18 enters second heat exchanger 20 with atemperature in the range of about +0° C. to +15° C. and transfers heatto third fluid 22 circulating in second conduit 24. Third fluid 22passes through third heat exchanger 25 and exchanges heat with fourthfluid 26. Fourth fluid 26 evaporates on receipt of heat from third fluid22 and enters second compressor 27 with a temperature of about +6° C.The second compressor 27 compresses the fourth fluid 26 to an elevatedtemperature and pressure. Fourth fluid 26 enters fourth heat exchanger28 with a temperature in the range of about +35° C. to +65° C. andtransfers heat to fifth fluid 31 circulating in third conduit 30. Thefifth fluid 31 exits fourth heat exchanger 28 with a temperature on theorder of +60° C. before circulating through the one or more radiators23.

Further reference is made to FIG. 7 in which an embodiment of a sewergas heat recovery system (SGHRS) 34 is shown. A second valuable sourceof heat may be recovered from a sewer gas exhaust, which is typicallyfilled with exhaust gases having a temperature of about 20° C. Thetemperature of the sewer gas exhaust remains relatively constant yearround. SGHRS 34 may be installed in a new or existing sewer gas exhaustpipe. The SGHRS 34 includes a heat recovery conduit 36 having a heatcollection portion 37 which is located in a sewer gas exhaust pipe 35.FIG. 9 shows a preferred location of the heat collection portion 37 ofthe heat recovery conduit 36 within a sewer gas exhaust pipe installedin a typical residential building. As shown in FIG. 9, the heatcollection portion 37 is preferably located in a section of the sewergas exhaust pipe 35 located above the uppermost sewage inflow pipe 35 aand below the roof. This location is beneficial because it maintains theheat collection portion 37 of the heat recovery conduit 36 free of fecalmatter and is typically the portion of the sewer gas exhaust pipe 35having the highest temperature. This in turn improves the energy balanceof the system. In alternative embodiments where the building has morethan one sewer gas exhaust pipe, the heat recovery conduit 36 may havemultiple heat collection portions 37 located in some or all of the sewergas exhaust pipes. While FIG. 9 shows the building sewage pipesconnected to a sanitary sewage system, the SGHRS will also work in thesame manner if the building sewage pipes are connected to a septic tank.

Referring again to FIG. 7, heat recovery conduit 36 also includes a heatexchange portion 38. In some embodiments, heat collection portion 37 mayhave a shape which maximizes the surface area of heat collection portion37 exposed to the gases flowing through the sewer gas exhaust pipe 35.Accordingly, in some embodiments, heat collection portion 37 maycomprise a coil or may define a tortuous path. It will be understoodthat the heat collection portion 37 may have any other suitable shape.The heat recovery conduit 36 may be of any suitable type, such as a pipeor a hose or a combination thereof.

A first heat recovery fluid 39 flows through the heat recovery conduit36. First heat recovery fluid 39 absorbs thermal energy when passingthrough the energy collection portion 37 of heat recovery conduit 36.The heat exchange portion 38 circulates first heat recovery fluid 39through first heat exchanger 16 of first thermocompressor 15. Theoperation of first thermocompressor 15 is the same as was described withreference to the EGRS 10. SGHRS 34 may include either a singlethermocompressor 15, as described above with reference to the firstembodiment of the EGRS 10, or first and second thermocompressors 15, 32as described above with reference to the second embodiment of the EGRS10. Consequently, the operation of thermocompressors 15, 32 will not befurther described.

Although the embodiment described in FIGS. 7 and 9 recovers heat from asewer gas exhaust pipe, in other embodiments, the same system canrecover heat from a ventilation duct of a building. Specifically, theheat collection portion 37 of the heat recovery conduit 36 may belocated inside a building ventilation duct. In all other respects, thisembodiment will operate identically to the embodiment of FIGS. 7 and 9.

Preferably, the SGHRS 34 and the EGRS 10 are each a system in whichheated fluid is supplied to heat fluid inside thermocompressors, withthe difference being the source of heat for the heated fluid. The SGHRS34 recovers heat from sewer exhaust gases and the EGRS 10 collects heatfrom a warmed air filled space beneath a roof covering.

In some embodiments, the two systems 10, 34 may be combined, as will nowbe described with further reference to FIG. 8. The combined system 45comprises the elements of both the SGHRS 34 and the EGRS 10 where acommon heat transfer portion 70 is connected to a SGHRS conduit 72 and aEGRS conduit 74. The SGHRS conduit 72 and EGRS conduit 74, includeenergy collection portions 37 and 12, respectively. The energycollection portions 37 and 12 are identical to those previouslydescribed. A first fluid 44 travels through the conduit formed by SGHRSconduit 72, EGRS conduit 74 and the heat transfer portion 70, asdescribed in more detail below. The first fluid 44 circulates throughfirst heat exchanger 16 of first thermocompressor 15. The operation offirst thermocompressor 15 in this embodiment is the same as previouslydescribed. Combined system 45 may include either a singlethermocompressor 15 or first and second thermocompressors 15, 32 aspreviously described.

The SGHRS conduit 72 and EGRS conduit 74 intersect at switching valve40. Preferably, the switching valve is a rotating 90 degree elbow valvelocated at the intersection of four pipes. The rotating elbow may becontrolled in any suitable fashion. Switching valve 40 may operate inone of at least three positions as described in more detail below.

In first switch position 41, switching valve 40 permits fluid from theSGHRS conduit 72 to circulate through the first heat exchanger 16, butprevents fluid from the EGRS conduit 74 from passing through the firstheat exchanger 16. In some embodiments, this may permit EGRS 10 toreceive maintenance or in cases of low outdoor temperatures this maypermit combined system 45 to operate at greater efficiency.

In a second switch position 42, switching valve 40 directs first fluid44 to pass through both the SGHRS conduit 72 and EGRS conduit 74 beforeentering first heat exchanger 16. Further, flow exiting first heatexchanger 16 does not directly re-enter energy collection portion 12,but instead flows through heat collection portion 37 of SGHRS 34.Preferably, second switch position 42 directs the flow of the firstfluid 44 to circulate through the heat collection portion 37 of theSGHRS conduit 72, then through the energy collection portion 12 of EGRSconduit 74 before exchanging heat with the first heat exchanger 16. Insome embodiments, this may permit combined system 45 to operate atgreater efficiency.

In third switch position 43, switching valve 40 permits fluid from theEGRS conduit 74 to circulate through the first heat exchanger 16, butprevents fluid from the SGHRS conduit 72 from passing through the firstheat exchanger 16. In some embodiments, this may permit SGHRS 34 toreceive maintenance.

It will be understood that the circulation of the various fluids of thesystems described herein may be effected by any number of suitable pumpsor other fluid motive means. Further, the operation of such pumps andany other electrical equipment, such as switching valve 40 (if it iselectrically controlled) may be effected by any suitable circuitry,sensors or other equipment. For instance, where a system describedherein is used to circulate hot fluid through radiators to heat abuilding, the speed of the various pumps, which circulate the fluids ofthe system, may be regulated according to thermostats in order toachieve and maintain a set-point temperature. Further, improvedefficiency may be achieved in any of the systems described herein bypowering any required electrical equipment with electricity produced byrenewable sources such as solar and wind powered generators.

The embodiments of the present invention provide numerous advantagesover the prior art. Specifically, they are an improvement overgeothermal systems because they eliminate the need to dig trenches orbore holes, which can add significant cost. In addition, the aboveembodiments can be retrofitted into existing buildings, and theinstallation does not depend on weather conditions or the geology ofbuilding location (i.e. whether the location is rocky or other adversegeological conditions). The embodiments of the present inventionfacilitate reduction in use of fossil fuels and electricity, therebybenefiting the environment.

While certain features of the invention has been illustrated anddescribed herein, many modifications, substitutions, changes, andequivalents will now occur to those of ordinary skill in the art. It is,therefore, to be understood that the appended claims are intended tocover all such modifications and changes as fall within the true spiritof the invention.

1. An energy generating roof system for a building roof comprising: aplurality of roof support members; a substantially planar vapor barrierlocated above the roof support members and operatively connectedthereto; a plurality of spacing members located above the vapor barrierand secured to the roof support members; a roof covering operativelyconnected to the spacing members, wherein the roof covering and thevapor barrier define an air filled space therebetween; a conduitcomprising an energy collection portion and a heat exchange portion,wherein the energy collection portion of the conduit is located withinthe air filled space, wherein the conduit is adapted to transport afirst fluid, wherein the first fluid is adapted to absorb thermal energywhen passing through the energy collection portion of the conduit; and afirst heat exchanger adapted to exchange heat with the first fluidpassing through the heat exchange portion of the conduit.
 2. The systemof claim 1 wherein a first pump circulates the first fluid through theconduit.
 3. The system of claim 1 further comprising a firstthermo-compressor system comprising: a second fluid adapted to circulatethrough the first heat exchanger and exchange heat with the first fluida first compressor in fluid communication with the first heat exchangerand adapted to compress the second fluid.
 4. The system of claim 3wherein the first thermo-compressor system further comprises: a secondheat exchanger in fluid communication with the first compressor andadapted to exchange heat with the second fluid.
 5. The system of claim 4wherein the first thermo-compressor system further comprises: a firstthrottle valve in fluid communication with the second heat exchanger andthe first heat exchanger and adapted to reduce the pressure of thesecond fluid.
 6. The system of claim 5 wherein the second heat exchangeris adapted to exchange heat between the second fluid and a third fluid.7. The system of claim 6 wherein the second heat exchanger is locateddownstream of the first compressor and the first throttle vale islocated downstream of the second heat exchanger and upstream of thefirst heat exchanger.
 8. The system of claim 6 wherein the third fluidis adapted to pass through at least one radiator and wherein the atleast one radiator is adapted to heat a building.
 9. The system of claim6 further comprising a second thermo-compressor comprising: a third heatexchanger adapted to exchange heat between the third fluid and a fourthfluid; a second compressor in fluid communication with the third heatexchanger and adapted to compress the fourth fluid; a fourth heatexchanger in fluid communication with the second compressor and adaptedto exchange heat with the fourth fluid; and a second throttle valve influid communication with the fourth heat exchanger and the third heatexchanger and adapted to reduce the pressure of the fourth fluid. 10.The system of claim 9 wherein the fourth heat exchanger is adapted toexchange heat between the fourth fluid and a fifth fluid.
 11. The systemof claim 1 wherein the energy collection portion of the conduit followsan undulating path comprising a plurality of straight segments and 180degree elbows.
 12. The system of claim 1 wherein the energy collectionportion of the conduit defines a tortuous path.
 13. The system of claim11 wherein the plurality of straight segments substantially align withspaces in between the spacing members.
 14. A sewer gas heat recoverysystem comprising; a sewer gas exhaust pipe; a heat recovery conduitcomprising an energy collection portion and a heat exchange portion,wherein the energy collection portion of the heat recovery conduit islocated within the sewer gas exhaust pipe, wherein the heat recoveryconduit is adapted to transport a first heat recovery fluid wherein thefirst heat recovery fluid is adapted to absorb thermal energy whenpassing through the energy collection portion of the heat recoveryconduit; and a first heat exchanger adapted to exchange heat with thefirst heat recovery fluid passing through the heat exchange portion ofthe heat recovery conduit.
 15. The system of claim 14 wherein the energycollection portion of the heat recovery conduit comprises a coil. 16.The system of claim 14 further comprising a thermo-compressorcomprising: a second fluid adapted to circulate through the first heatexchanger and exchange heat with the first heat recovery fluid; a firstcompressor in fluid communication with the first heat exchanger andadapted to compress the second fluid; a second heat exchanger in fluidcommunication with the first compressor and adapted to exchange heatwith the second fluid; and a first throttle valve in fluid communicationwith the second heat exchanger and the first heat exchanger and adaptedto reduce the pressure of the second fluid.
 17. The system of claim 16wherein the second heat exchanger is adapted to exchange heat betweenthe second fluid and a third fluid.
 18. The system of claim 17 furthercomprising a second thermo-compressor comprising: a third heat exchangeradapted to exchange heat between the third fluid and a fourth fluid; asecond compressor in fluid communication with the third heat exchangerand adapted to compress the fourth fluid; a fourth heat exchanger influid communication with the second compressor and adapted to exchangeheat with the fourth fluid; and a second throttle valve in fluidcommunication with the fourth heat exchanger and the third heatexchanger and adapted to reduce the pressure of the fourth fluid. 19.The system of claim 17 wherein the third fluid is adapted to passthrough at least one radiator and wherein the at least one radiator isadapted to heat a building.
 20. A combined sewer gas heat recovery andenergy generating roof system comprising: an energy generating roofsystem (EGRS) comprising: a plurality of roof support members, asubstantially planar vapor barrier located above the roof supportmembers and operatively connected thereto, a plurality of spacingmembers located above the vapor barrier and secured to the roof supportmembers, a roof covering operatively connected to the spacing members,wherein the roof covering and the vapor barrier define an air filledspace therebetween, and a EGRS conduit comprising an energy collectionportion, wherein the energy collection portion of the conduit is locatedwithin the air filled space, wherein the conduit is adapted to transporta first fluid, wherein the first fluid is adapted to absorb thermalenergy when passing through the energy collection portion of theconduit; a sewer gas heat recovery system (SGHRS) comprising: a sewergas exhaust pipe, and a SGHRS conduit comprising an energy collectionportion, wherein the energy collection portion of the SGHRS conduit islocated within the sewer gas exhaust pipe, wherein the SGHRS conduit isadapted to transport the first fluid wherein the first fluid is adaptedto absorb thermal energy when passing through the energy collectionportion of the SGHRS conduit; a first heat exchanger adapted to exchangeheat with the first fluid; and a switching valve in fluid communicationwith the EGRS conduit and the SGHRS conduit, wherein the switching valveis operable between: a first position wherein the first fluid isdirected through the energy collection portion of the SGHRS conduit butis prevented from passing through the energy collection portion of theEGRS conduit; a second position wherein the first fluid is directedthrough the energy collection portion of the SGHRS conduit and throughthe energy collection portion of the EGRS conduit; and a third positionwherein the first fluid is directed through the energy collectionportion of the EGRS conduit but is prevented from passing through theenergy collection portion of the SGHRS conduit.
 21. The combined systemof claim 20 further comprising a thermo-compressor comprising: a secondfluid adapted to circulate through the first heat exchanger and exchangeheat with the first fluid; a first compressor in fluid communicationwith the first heat exchanger and adapted to compress the second fluid;a second heat exchanger in fluid communication with the first compressorand adapted to exchange heat with the second fluid; and a first throttlevalve in fluid communication with the second heat exchanger and thefirst heat exchanger and adapted to reduce the pressure of the secondfluid.
 22. The system of claim 21 wherein the second heat exchanger isadapted to exchange heat between the second fluid and a third fluid. 23.The system of claim 22 further comprising a second thermo-compressorcomprising: a third heat exchanger adapted to exchange heat between thethird fluid and a fourth fluid; a second compressor in fluidcommunication with the third heat exchanger and adapted to compress thefourth fluid; a fourth heat exchanger in fluid communication with thesecond compressor and adapted to exchange heat with the fourth fluid;and a second throttle valve in fluid communication with the fourth heatexchanger and the third heat exchanger and adapted to reduce thepressure of the fourth fluid.
 24. A ventilation duct heat recoverysystem comprising; a ventilation duct; a heat recovery conduitcomprising an energy collection portion and a heat exchange portion,wherein the energy collection portion of the heat recovery conduit islocated within the ventilation duct, wherein the heat recovery conduitis adapted to transport a first heat recovery fluid wherein the firstheat recovery fluid is adapted to absorb thermal energy when passingthrough the energy collection portion of the heat recovery conduit; anda first heat exchanger adapted to exchange heat with the first heatrecovery fluid passing through the heat exchange portion of the heatrecovery conduit.